[RemotePlayback] Don't expose Remote Playback API for WebView.

android_webview/lib/main/aw_main_delegate.cc

Index: android_webview/lib/main/aw_main_delegate.cc
diff --git a/android_webview/lib/main/aw_main_delegate.cc b/android_webview/lib/main/aw_main_delegate.cc
index 6f2c92fbe8e4a1324f6ab4c6ac715a29cf524c1b..6236e19f0bcb67929e3b13b53d2c741bd4bbd522 100644
--- a/android_webview/lib/main/aw_main_delegate.cc
+++ b/android_webview/lib/main/aw_main_delegate.cc
@@ -107,6 +107,10 @@ bool AwMainDelegate::BasicStartupComplete(int* exit_code) {
   // https://crbug.com/521319
   cl->AppendSwitch(switches::kDisablePresentationAPI);
 
+  // WebView doesn't support Remote Playback API for the same reason as the
+  // Presentation API, see https://crbug.com/521319.
+  cl->AppendSwitch(switches::kDisableRemotePlaybackAPI);
+
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
   if (cl->GetSwitchValueASCII(switches::kProcessType).empty()) {
     // Browser process (no type specified).